Apparatus for converting a reciprocating motion into unidirectional rotation

ABSTRACT

The apparatus has the form of a non-self-braking helical mechanism located inside casing (24) and having a driving member (2) and a driven member (1) connected to the driving member (2) through rolling bodies (3). The driving member (2) is connected to unit (5) for applying an axial force to ensure free axial displacement, free rotation, locking, and engagement with two surfaces, of which one is a locking surface, and the other is a sliding surface, with corresponding identical surfaces of the unit (5). The unit (5) is connected to a mechanism for generating an axial force in the form of a helical transmission (9, 11) ensuring generation of a torque to change the turning angle of the driven member (1), and has a mechanism (17) for varying the axial force. Driving member (9) of helical transmission (9, 11) is positioned coaxially with the driven member (1) and rigidly connected to unit (5) and to mechanism (17) for engagement with the driving and driven members (2, 1).

FIELD OF THE INVENTION

This invention relates to the art of transmitting rotation to objects,and more particularly to an apparatus for converting a reciprocatingmotion into unidirectional rotation.

BACKGROUND OF THE INVENTION

There is known a device for converting a reciprocating motion intounidirectional rotation (PCT/SU90/00280) in the form of anon-self-braking helical mechanism housed in a casing. The helicalmechanism has a driving member in the form of a screw with a unit forapplying an axial force, and a driven member in the form of a nutjournaled in bearings inside the casing and connected to the drivingmember through rolling bodies. The driven and driving members make up ahelical rolling transmission. Connected to the unit for applying anaxial force is a mechanism for generating and varying this forcefashioned either as a controllable power cylinder, or as a hinged-leversystem capable of smoothly varying the ratio between the lever arms.

However, the known hinged-lever mechanisms for generating and varying anaxial force produce radial component forces that negatively affect theefficiency of the axial force application unit in operation by causingits deformation and skewing. Also, the power elements of such systems,for example, the casing taking up the forces of reaction from forcesexerted on the driven member must have substantial dimensions and weightto provide the required rigidity.

SUMMARY OF THE INVENTION

This invention is directed toward the provision of an apparatus forconverting a reciprocating motion into unidirectional rotation in whichby virtue of varying the engagement of a mechanism for generating anaxial force, unit for applying an axial force, driving and drivenmembers it would be possible to ensure the movement, smooth braking,reversing, free inertia rotation in one direction through preventingrotation in the opposite direction, and free rotation in any direction.

The object of the invention has been attained by that in an apparatusfor converting a reciprocating motion into unidirectional rotation inthe form of a non-self-braking helical mechanism housed in a casing andhaving a driving member with a unit for applying an axial forceconnected to this driving member and to a mechanism for generating anaxial force and provided with a mechanism for varying this force, thedriving member being connected to the unit for applying an axial forcefor free axial displacement, free rotation, locking, and engagement byits two surfaces, of which one is a locking surface and the other is asliding surface, with corresponding identical surfaces of the unit forapplying an axial force, and also having a driven member connected tothe driving member through rolling bodies and capable of rotating aboutits own axis, according to the invention, the mechanism for generatingan axial force has the form of a helical transmission providing a torqueto change the turning angle of the driven member, the driving member ofthe helical transmission being positioned coaxially with the drivenmember and rigidly connected to the unit for applying an axial force forengagement with the driving and driven members.

Provision of the mechanism for generating an axial force in the form ofa helical transmission allows to prevent the appearance of parasiticcomponents of the axial force causing deformation and skewing of theunit for applying the axial force and reducing the general efficiency ofthe apparatus. The driving force acts in a plane parallel with the planeof rotation of the driving member. Forces of reaction resulting from theforces applied to the driven member are closed up inside the apparatus,therefore allowing to substantially reduce the mass and lineardimensions of the power members taking up these forces, such as thecasing. In addition, the driving and motion-converting helicaltransmissions can be arranged coaxially to still further reduce the sizeof the mechanism.

The unit for applying an axial force engages both with the driving anddriven members of the helical transmission converting the motion. Inorder to convert the motion, use is made, apart from the axial force, ofa torque produced by the driven member.

It is advisable to provide the apparatus with an additional drivingmember connected to the unit for applying an axial force for engagementtherewith, an additional driven member rigidly connected to the drivingmember, and a braking unit rigidly connected to the driving member ofthe helical transmission for engagement with the additional drivenmember; outer thread of the additional driving member having a directionopposite to thread direction of the main driving member.

Such an arrangement allows to obtain a continuous rotation of the drivenmembers by using one driving member of the helical transmission, andalso to differentiate the direct and reverse forces.

For obtaining a continuous rotation from two independent power sources,the apparatus is preferably provided with an additional driving memberhaving a separate unit for applying an axial force connected to thedriving member of the helical transmission of an additional mechanismfor generating the axial force positioned coaxially with the drivenmember of the main mechanism for generating the axial force, and with anadditional driven member rigidly connected to the main driven member. Inthis arrangement the casing is made up of parts, each such part beingconnected to the corresponding driven member through bearings and toother members of the helical transmissions engaging with the drivingmembers.

This construction allows to accommodate the driven members between twosupports and reduce the size of the apparatus.

To ensure smooth braking at any point in time in any position of thedriven members when changing the direction of one of acting forces, itis necessary that the apparatus be provided with a flexible linkageenabling engagement of the driven members and fashioned as springslocated inside the driving members of the helical transmissions bearingon projections made at their inner surface and forcing the drivingmembers to each other through rolling bodies by an adjustment screw andthrust bearings. It is also preferable to provide the apparatus with abraking mechanism having a flexible member rigidly connected to one ofthe units for applying an axial force, capable of engagement with theother unit for applying an axial force, and provided with brake shoescooperating with the driven member in one direction of the forcesexerted on the levers of the mechanisms for varying the axial forces.

In an alternative embodiment of the proposed apparatus the drivingmembers of helical transmissions are adapted to engage with each otherthrough rolling bodies.

The abovedescribed arrangement of the driving members allows a motionconversion by using two separate drives; one such drive transmissionforces to the other to combine the action of oppositely directed forces.

Alternatively, the driving members of the helical transmissions areconnected to each other through rolling bodies and rigid members fortheir relative rotation and simultaneous travel of the driving membersin one direction while preventing their relative movement in theopposite directions.

This feature of the invention synchronizes the movement of the drivelevers as pressure force is exerted on one of these levers. It alsoaffords to combine the drive forces and to use the drive levers assupports.

Preferably, each unit for applying an axial force is made integral withthe corresponding driving member, the units for applying axial forcesare rigidly interconnected, whereas the driving members are connected byrolling splines to the casings. Other members of the helicaltransmissions engaging with the driving members are also connected tothe casings for rotation. In addition, each part of the casing ispreferably provided with annular cavities to accommodate the driven anddriving members.

This gives the advantage of applying drive forces in the plane ofrotation of the levers. A combination of the units for applying axialforces with the driving members ensures reduced overall dimensions ofthe apparatus.

It would be advisable to provide the apparatus with a multi-positionswitch for reversing and braking of the driven member after stopping,this switch being moved and locked relative to the unit for applying anaxial force to brake the driven member as it rotates in any direction,and to allow free rotation of the driven member in one direction andprotect it against rotation in the opposite direction. In the positionof the multi-position switch corresponding to a braking action the totalvalue of clearances between the engaging locking surfaces of the unitfor applying an axial force and switch should preferably be smaller thanthe total value of clearances between their sliding surfaces. The valueof clearance between the locking surfaces at either side should be lessthan the value of clearance between the sliding surfaces.

It is advisable that such a multi-position switch be provided withthrust rings of bearings with rolling bodies connected to a sliding nutmounted on the driven member for reciprocations therealong and lockingby a control handle rigidly connected to the driven member to ensureengagement of locking and sliding surfaces of the unit for applying anaxial force and driving member in the course of reversing and brakingafter stopping the driven member.

This construction of the multi-position switch allows to use easilydetachable drive levers.

The proposed apparatus can be additionally provided with amulti-position switch ensuring reversal and free rotation of the drivenmember in any direction and capable of being moved and locked relativeto the unit for applying an axial force providing free rotation of thedriven member in any direction, as well as free rotation of this memberin one direction with protection against rotation in the oppositedirection; in a position of this switch corresponding to free rotationof the driven member in any direction the total value of clearancesbetween engaging locking surfaces of the unit for applying an axialforce and switch must be greater than the total value of clearancesbetween their sliding surfaces; the value of clearance between thelocking surfaces at either side must preferably be greater than thevalue of clearance between the sliding surfaces; or, alternatively, theapparatus may be provided with two multi-position switches ensuringreversal of continuous rotation, free rotation of the driven members inone direction and protection against their rotation in the oppositedirection, free rotation of the driven members in any direction andbraking of the driven members rotating in any direction; each suchmulti-position switch being moved and locked relative to thecorresponding unit for applying an axial force; in the position of eachmulti-position switch corresponding to a braking action the total valueof clearances between engaging locking surfaces of each switch andcorresponding unit for applying an axial force being preferably greaterthan the total value of clearances between their sliding surfaces; thevalue of clearance between the locking surface at either side beingpreferably greater than the value of clearance between the slidingsurfaces.

It would be most advisable to provide each multi-position switch with ahollow rod rigidly secured to the unit for applying an axial force andadapted to be locked and reciprocated axially relative to the drivingmember by a control handle with a lock member; the unit for applying anaxial force should preferably have an additional locking surface to acton the driving member by an additional oppositely directed force,whereas the driving member should be connected to the driving memberthrough rolling bodies received in radial-thrust rings rigidly connectedto the driving member.

This arrangement allows to reduce the size of the mechanism forobtaining continuous rotation of the driven members.

In addition, the proposed apparatus can be further provided with amechanism for producing a torque transmitted to the unit for applying anaxial force connected thereto, and a mechanism for varying the torque inresponse to variations in the axial force, the two mechanisms beinginterconnected. Provision of such mechanisms allows to substantiallychange the torque without increasing the axial forces.

In order to use the proposed apparatus in situations requiringsubstantial torques or high speed, it is necessary that the mechanismfor producing the torque be provided with a locking member ensuring itsrigid connection to the mechanism for varying the axial force.

It is advantageous that the mechanisms for varying the axial force andtorque be integrated into one mechanism in the form of a telescopinglever connected to the driving member of the helical transmission inturn rigidly linked to the unit for applying an axial force. This allowsto change the output characteristics of the driven member.

For improving engagement of the driving members with the units forapplying axial forces it is preferable that their locking surfaces befabricated from steel, and their sliding surfaces be defined by rollingbodies.

To separate the stroke of the driving member resulting in a movement ofthe driven member, and the stroke executing a braking action of thedriven member, the driving member is provided with adjustable stopsintended to prevent or ensure engagement of the unit for applying anaxial force with the driven member on friction elements of smooth andemergency braking located at the opposite sides of the unit for applyingan axial force and connected to the driven member; the stops arefabricated from a resilient material.

Projections having tops thereof engaging with the surface of the flangeof the driving member are provided to separate a film of oil in theclearance between the unit for applying an axial force and flange of thedriving member at the end surface of the unit for applying an axialforce.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail with reference tospecific examples of its embodiments taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a general view of an apparatus for converting a reciprocatingmotion into unidirectional rotation according to the invention;

FIG. 2 shows an embodiment of the proposed apparatus capable ofgenerating a continuous inertia rotation;

FIG. 3 is a modification of the apparatus with two driving and twohelical transmissions converting the motion;

FIG. 4 is a fragmentary view of the same as illustrated in FIG. 3without engagement between the driving members;

FIG. 5 shows a modified form of the apparatus with two separate movementconversion and two driving helical transmissions, the driving membersthereof being capable of relative engagement;

FIG. 6 shows an alternative arrangement, in which the driving members ofhelical transmissions are connected through rolling bodies and rigidelements;

FIG. 7 illustrates a modification of the apparatus, in which each unitfor applying an axial force is made integral with the correspondingdriving member;

FIG. 8 shows one more construction of the apparatus capable of reversingthe unidirectional rotation of the driven member and braking thereofafter stopping;

FIG. 9 is a modified form of the apparatus ensuring reversal and freerotation of the driven member in any direction;

FIG. 10 shows a modification with two helical mechanisms; and

FIG. 11 shows a modification of the apparatus comprising mechanism forproducing and varying a torque.

BEST MODE OF CARRYING OUT THE INVENTION

Apparatus for converting a reciprocting motion into unidirectionalrotation comprises coaxial helical transmissions. The other helicaltransmission executing the conversion is a ball-bearing transmission,i.e., a nut of driven member 1 (FIG. 1) has annular grooves receivingballs 3 equal in number to the number of screw starts in driving member2. The screw of driving member 2 has flange 4 press-fitted thereon toengage with unit 5 for applying an axial force in the form of a thrustdisk with hub and a radial thrust ring locked in place by ring 6. Thedriving member 2 cooperates with axial play with unit 5 for applyingaxial force through balls 7 and separator 8. In addition, end face ofthe thrust disk of unit 5 facing the flange 4 of the driving member 2has, for example, concentric projections 5a whose sharp tops engage withthe surface of flange 4. Inner driving helical transmission serves as amechanism for producing an axial force, provides torque transmitted tothe unit 5, and comprises a driving member 9 in the form of a hollowscrew rigidly connected to the thrust disk of unit 5 and having amultistart thread of enhanced pitch. The driving member 9 engagesthrough intermediate rolling bodies in the form of balls 10 with fixednut 11 having inner rings 12 to protect the balls 10 against fallingout. The nut 11 of the driving helical transmission is rigidly connectedto collet shell 13 through a spline joint, nut 142 with flexiblemembrane 15, and lock washer 16. The direction of threads in the innerand outer helical transmissions can be different. The driving member 9is rigidly linked with a telescoping lever 17 of mechanism for varyingthe axial force, and is provided with a stop 18 in the form of aresilient ring member. A friction ring 19 for emergency braking issecured to the end face of the nut of the driven member 1 facing thethrust disk of unit 5. In this case the inner and outer helical pairshave left-hand threads. To ensure a smoother braking, the apparatus hasa brake flange 20 secured to the nut of the driven member 1. The drivenmember 1 is connected to an actuating mechanism, such as wheel 21. Inaddition, this member 1 is mounted on bearings 22 and 23 inside thecollet shell 13 which is rigidly secured in casing 24 havinglongitudinal projections adapted to be received by split grooves of thecollet shell 13 and fixed in place by stop ring 25. The casing 24 ismounted on a post 26.

To ensure continuous inertia rotation of the wheel 21, the apparatus isprovided with a driven member 27 (FIG. 2) rigidly connected to thedriven member 1 and wheel 21, and engaging through intermediate rollingbodies 28 with an additional driving member 29. The driving member 29has outer threads of a direction opposite to the thread direction of thedriving member 2. The driving member 29 and flange 30 are connected byway a radial thrust ring 31 and balls 32 to separator 33 and unit 34 forapplying axial force in the form of a double-action disk with a hubrigidly connected to the driving member 9 also rigidly linked with abraking unit fashioned as cup-shaped friction member 35 engageable withthe driven member 27.

In order to ensure continuous rotation and inertia motion from the twodriving members, the apparatus is further provided with a driving member36 (FIG. 3) in the form of a screw connected through rolling bodies 37,such as balls, to a separate unit 38 for applying axial force through aradial thrust ring 39, and a driven member 40 in the form of a nutrigidly connected to the nut of the driving member 1. The members 36 and40 are connected by means of rolling bodies 41 in the form of ballsreceived in annular grooves made at the surfaces of members 36 and 40facing each other. Outer surfaces of the driving members 2, 36 haveoppositely directed threads. The apparatus is additionally provided witha mechanism for producing an axial force in the form of a helicaltransmission comprising a driven member 42 fashioned as a hollow screwwith enhanced thread pitch mounted coaxially with the driving link 9 andrigidly connected to the thrust disk of unit 38 and connected to thedrive member 42 through rolling bodies in the form of balls 43, andfixed nut 44 having inner rings 45 to protect balls 43 against fallingout. The driving members 9 and 42 have outer threads of differentdirections. The nut 44 is rigidly connected through spliens, locking nut46 and stop 47 to a collet shell 48 mounted inside a casing 49. Thedriven member 40 is journaled in bearings 50, 51 of the collet shell 48.The driving member 42 is rigidly connected to an additional mechanismfor varying the axial force in the form of a telescoping lever 52. Endsurfaces of the drive members 9 and 42 facing each other have annulargrooves adapted to receive rolling bodies in the form of balls 53. Theseballs 53 are separated and held against falling out by a separator 54movably connected to one of the drive members 42 or 9.

The driving members 9, 42 are urged to each other by springs 55compressible through thrust bearings 56 by adjustment screw 56 with nut58.

Also, the apparatus has a brake mechanism comprising a cup-shaped platesteel spring 59 having a central hole and rigidly connected by screws 60to the thrust disk of the unit 5 engaging with a conical projection 61of the unit 38 and provided with brake shoes in the form of frictionlinings 62.

Referring now to FIG. 4, there is shown an alternative embodiment of theproposed apparatus, in which the driving members 9 and 42 are notconnected and fail to engage with each other.

FIG. 5 shows another embodiment of the apparatus, in which the drivingmembers 9 and 42 are not connected, but are intended to engage with eachother through rolling bodies in the form of balls 53 with a movableseparator 54 connected to the driving member 42.

The driving members 9 (FIG. 6) and 42 can be connected through thrustbearings 63 forced against inner shoulders 64, 65 of the driving members9 and 42, and rigid elements of a helical brace in the form of screw 66and nut 67.

FIG. 7 shows an alternative embodiment of the apparatus, in which thethrust disk of each unit 5 and 38 for applying axial force is madeintegral with corresponding driving members 68 and 69 generallyfashioned as a nut. In addition, the driving members 68 and 69 arerigidly axially connected by a bayonet lock 70. The members 68 and 69are further connected through outer splines 71, 72 to collet casings 73,74 whose annular cavities 75, 76 accommodate the driven and drivingmembers 1, 40, 2, 36. Other members 77, 78 of the helical transmissionfashioned as screws connected to nuts of driving members 68, 69 throughrolling bodies, such as balls 79, 80, are secured by means of thrustbearings 81, 82 and nuts 83, 84 with stops 85, 86.

In order to reverse the unidirectional rotation and execute a brakingaction after stopping the driven member 1 (FIG. 8), the proposedapparatus has a multi-position switch. In this case unit 87 for applyingan axial force is preferably fashioned as a disk with a hub engageableby its outer tapered steel surfaces with inner steel surfaces of ahollow flange assembly 88 rigidly connected to the driving member 2. Thedisk 87 has ports to receive fastening elements 89 rigidly connectingand centering thrust rings 90 of bearings of the multi-position switchwith balls 91 and separators 92. The fastening elements 89 are connectedto the rim of a sliding nut 93 by way of stop rings 94. The sliding nut93 is connected to the driving member 9 by a threaded connection. It isalso rigidly connected by screws 95 to a control handle linked toflexible plate 97 having a projection to lock it in one of three groovesof driving lever 17 by a lock mechanism 98. The travel path of drivingmember is limited at one side by the membrane 15 of nut 14, and at theother side by nut 11 and flexible ring of stop 18. A coaxial casing 99fabricated from a high-friction material and rigidly connected to thedriven member 1 serves to ensure smooth braking.

In FIG. 8 all clearances between the engaging locking and slidingsurfaces of the disk 87 and driving member 2 are indicated by referencecharacters a, b, c, d. In the middle corresponding to a braking actionthe clearances a, b, c, d are distributed in such manner that the totalvalue (a+c) of clearances a, c between the engaging locking surfaces ofthe disk 87 and flange 88 of the driving member 2 is smaller than thetotal value (b+d) of clearances b, d between their sliding surfaces,i.e., a+c<b+d, and the following inequalities must be fulfilled:

    a<b and c<d.

Alternatively, the proposed apparatus may be provided with amulti-position switch ensuring reversal and free rotation of the drivenmember 1 (FIG. 9) in any direction thanks to changing the engagement ofthe driving link 2 with unit 100 for applying an axial force fashionedin this case as a hollow flange assembly engageable with disk 101 of thedriving member 2. Radial-thrust annular grooves of the inner projectionof the driving member 2 receive balls 102 embraced by split rings 103fixed in place by a stop ring 104 on the driving member 9. The flange ofunit 100 is threadedly connected to a hollow rod 105 of multi-positionswitch linked to the driving member 9. Secured to tailpiece of rod 105by anchor 106 and nut 107 is a control handle 108 affixed to a flexibleplate 109 and provided with lock 110. The handle 108 is stopped in oneof three positions. The apparatus also has casing 111 secured to a lever112.

An embodiment of the proposed apparatus shown in FIG. 10 comprises ahelical mechanism II positioned in symmetry with the helical mechanismI. The mechanism II has a construction substantially similar to theconstruction of the mechanism I, and includes the following parts:driven member 113, bearings 114, 115, balls 16, driving member 117 withdisk 118, split rings 119, stop ring 120, driven member 121, balls 122,fixed nut 123, balls 124, stop nut 125, collet casing 126, flange 127 ofaxial force application unit, hollow rod 128 of multi-position switch,casing 129, anchor 130, nut 131, flexible plate 132, control handle 133,lock 134, lever 135, casing 136, and post 137.

With reference to the apparatus shown in FIGS. 9 and 10, in the middleposition of the flexible plate 109 with control handle 108 of the switchthe clearances b and d between rolling friction surfaces are smallerthan the clearances a and c between sliding friction surfaces a>b andc>d, whereby the driven members 1, 113 can rotate in any direction. Endpositions of the switch correspond to the movement of driven members 1and 113 to one side, and rotation in the opposite direction isprevented. Therewith, a<b and c>d, or a>b and c<d.

The apparatus illustrated in FIG. 11 has a mechanism for producing atorque in the form of lever 138 and mechanism for varying torque in theform of a telescoping lever 139, the two mechanisms being operativelyconnected to each other. The lever 138 is rigidly connected to theflange of a sleeve serving as a unit 140 for applying axial force andmounted for rotation on rolling bodies 141 to be also locked by stopmember 142 on rod 143 of the mechanism for varying the axial force. Thislatter mechanism also includes a connecting rod 144 linked by shafts 145to rod 143 and to telescoping lever 146 adapted to rotate on shaft 147.Movement of of the sleeve of unit 140 axially on rod 143 is limited bylug 148 provided on rod 143 and stop ring 149. Stop member 142 can bemoved on the lever 139. The rod 143 is received in guide sleeve 150having linear bearings 151, and is rigidly connected by nut 14 to shell13 affixed by means of stop ring 25 and spline joint to casing 24. Thecasing 24 and shaft 147 are rigidly connected to post 26.

The herein proposed apparatus for converting reciprocation motion intounidirectional rotation operates in the following manner.

With the greatest length of the telescoping lever 17 (FIG. 1) movementof the operator's hand causes this lever to travel from one end positionto the other. In turn, the driving member 9 in the form of a screwrigidly connected to the lever 17 executes reciprocation together withthe unit 5 on the fixed nut 11. The unit 5 moves to each side to engagewith the driving member 2 either through the flange 4, or through theballs 7. The driving member 2 rotates the driven member 1. In the courseof movement of the unit 5 toward nut 14 the force is transmitted fromunit 5 to driving member 2 through flange 4. Therewith, the disk of unit5 having sharp concentric projections 5a acts to bite through an oilfilm to ensure a clutching or locking action.

When the direction of rotation of the driven member 2 and driving member9 coincide, the turning angle of the driven member 1 increases to avalue proportional to the turning angle of the driving member 9.Conversely, when the direction of rotation of these members is opposite,the turning angle of the driven member 1 will be reduced by the samevalue. This is generally associated with the preferred thread pitch ofthe driving member 9 and helical transmission influencing a change inthe torque or the speed of rotation. In the course of a reversemovement, that is away from nut 14, the unit 5 acts on the drivingmember 2 through rolling bodies in the form of balls 7. Since the momentof inertia of the driving member 2 is substantially lower than that ofthe driven member 1, then in any case the driving member 2 will executea helical movement relative to the driven member, and the direction ofrotation of these members 1 and 2 will coincide.

With the maximum length of the lever 17 and optimized amplitude ofmovements it will have the least turning angle, and the driving member 9will execute helical movement to travel a distance which is only afraction of the maximum travel path. Within the travel path in themovement of the driven member 1 it is possible to vary the initialpositions and frequency of movements of the lever 17. At any point intime and in any position it is possible to stop the lever 17, wherebythe driven member 1 will force it by its threaded surface through balls3 to the rolling friction surface of unit 5 to rotate this unit 5 withno resistance to rotation. In order to increase the speed of motion,particularly when an increase in the frequency of movements makes nosense, the length of lever 17 should be preferably reduced to therebyincrease its turning angle. This will lead to an increase in the travelpath of the driving member 9, and consequently to a greater turningangle of the driven member 1. Therefore, by varying the amplitude,frequency of motions of lever 17, and changing its end positions and itslength it is possible to select the required conditions for the movementof the driven member 1 and wheel 21, for example, of a sportingwheelchair.

In order to execute a smooth braking action, it is necessary to apply aforce sufficient to overcome the force of the flexible ring of stop 18.The unit 5 is brought into engagement with the brake flange 20, and afriction torque produces a repulsive force therebetween. For emergencybraking it is necessary to overcome the force of flexible membrane 15 ofnut 14. The unit 5 engages with friction ring 19, and the braking torquetends to enhance their engagement leading to self-tightening of thedriven member 9.

When using tow outer helical transmissions, the common force applicationunit 34 (FIG. 2) initiates simultaneous movement of the two drivingmembers 2 and 29. One such member rotates the rigidly linked drivenmembers 1 and 27 to act thereon through flanges 4 or 30, whereas theother driving member 2 or 29 executes engagement through balls 7 and 28to be unscrewed from the corresponding driven member 1 or 27. In thismanner a continuous rotation of wheel 21 is ensured. When the action offorces is terminated, rotation by inertia continues. More particularly,thanks to the action of driven members 1 and 27 a clearance is formedbetween flanges 4 and 30. Therewith, the driving members 2 and 29continue to rotate and at the same time to engage with the unit 34through balls 7 and 32. Braking action is effected when the frictionmember 35 exerts force on the driven link 27 and the end face of member9 engages with the membrane 15, although this requires overcoming theresistance of the flexible membrane 15.

This construction of the apparatus ensuring continuous rotation of thedriven members 1, 27 and rotation by inertia is especially efficientwhen used as a drive of a wheelchair. In the course of the travel oflever 17 away from the operator, that is when his arms extend and hisback is pressed against the seat-back of the wheelchair, the forceexerted on the lever 17 is substantially greater than the force producedby the operator as his arms move in the opposite direction. Taking thisfact into consideration, the direction of threads in the members 9, 11,1, 27, 2, and 29 is such that in the course of moving the lever 17 awayfrom the operator the direction of rotation of the driven members 1 and27 coincides with the direction of rotation of the driving member 2 or29 engaging therewith, that is the turning angle of the driven members 1and 27 increases. When the lever 17 is moved toward the operator, a liketorque is produced in the driven members 1 and 27, although under theaction of a lesser force due to that the driving member 29 turns in adirection opposite to rotation of the driven members 1 and 27.

The apparatus shown in FIG. 3 can be used with success in amuscle-driven vehicle. In this case the members 9, 11 and 42, 44 of thehelical transmissions have threads of different direction; this beingalso true with respect to the direction of threads in this members 1, 2and 40, 36. As the lever 52 is moved away from the operator, the drivemember executes a helical motion, and the member 38 acts on the flangeof driving member 36 to rotate the driven member 40. At the same time,the driven member 42 acts through springs 55 and thrust bearings 56 onthe driving member 9 which executes a helical motion with the directionof rotation opposite to the direction of rotation of the driving member42. Movement of the member 9 causes the unit 5 to exert pressure throughballs 7 on the flange of the driving member 2 which is screwed out ofthe the driven member 1.

When the travel of lever 53 is changed to the opposite, direction ofrotation of the driven member 42 is also changed. Movement from thedriven member 42 is transmitted through the balls 53 to the drivingmember 9, and the unit 5 acts on the flange of the driving member 2,which in turn rotates the driven members 1, 40 and wheel 21. At the sametime, the driving member 42 exerts force through balls 37 on the drivingmember 36 to bring it out of the driven member 40. In this member thealternating action of oppositely direction forces on the lever 52 causescontinuous rotation of wheel 21; the torque force of springs 55 beingpreferably in excess of the clutch force of the driving members 42 and9.

When simultaneously exerting oppositely directed forces on the levers 17and 52, such as during the movement of the lever 52 away from theoperator and lever 17 toward the operator, rotation of the drivingmember 42 will cause the unit 38 to act on the flange of the drivingmember 36. At the same time, the driving member 9 also executing ahelical motion will act mostly on the member 38 and driving member 36,and will exert a minor force on the driving member 2 through balls 7.This engagement will cause the driven member 40 to rotate, whereas thedriving member 2 will execute helical motion relative to the drivenmember 1. As a result, the forces of the driving members 9 and 42 torotate the wheel 21 will be combined.

Changing the direction of force exerted on any of the levers 17 or 52 inany position thereof will cause a braking action due to that the drivingmembers 9 and 42 with oppositely directed outer threads depart from eachother. The conical projection 61 of unit 38 will force the spring 59 tobring the friction linings 62 into engagement with the driving links 1and 40.

The total working stroke of the driving members 9 and 42 is limited bythe distance between the end surfaces of fixed nuts 11 and 44 facingeach other.

In the absence of cooperation between the driving members 42 and 9 (FIG.4) the units 5 and 38 engage independently with their respective drivingmembers 2 and 36. Here, the action of oppositely directed forces exertedon the levers 17 and 52 (FIG. 3) ensures continuous rotation of wheel 21(FIG. 4) by virtue of alternating rotation of the driven members 1 and40. In response to a simultaneous application of unidirectional forcesto the levers 17 and 52 (FIG. 3) the motion is converted when the levers17 and 52 are moved only in one direction; their travel in the oppositedirection results in idling.

The modified form of the proposed apparatus in which driving members 42and 9 (FIG. 5) engage through rolling bodies in the form of balls 53operates as follows. The driving members 42 and 9 connected,respectively, to the levers 52 and 17 (FIG. 3) engage independentlythrough the units 5 and 38 with the driving members 2 and 36 to rotatethe driven members 1 and 40. Rotation of the driven members 1 and 40 isalso possible in response to the action of oppositely directed forcesapplied to the levers 17 and 52 (FIG. 3) which results in thetransmission of forces from one driving member 42 to the other member 9,or vice versa, i.e., the motion conversion forces are combined. Thismodification of the apparatus according to the invention can be used asa bicycle drive assembly. In this case, the bicycle rider exerts theforce of arms and legs on the levers 17, 52. Separate pushing movementsof arms and legs, or even their joint pushing and pulling actions arepossible.

The alternative modification of the proposed apparatus where the drivingmembers 42 and 9 (FIG. 6) are connected through balls 53, thrustbearings 63, and rigid elements in the form of screw 66 and nut 67 makesit possible to combine the forces transmitted to the driving members 42,9 and synchronize the movement of these members. With an equality offorces exerted on the two driving members 42 and 9 these forces aremutually compensated and thereby the apparatus fails to convert themotion. When using this modification is a bicycle drive, foot pedals aremounted on the levers 17 and 52 (FIG. 3). Pressure applied to one of thepedals will cause rotation of the driven members 42 and 9 (FIG. 6) andwheel 21, the other pedal and corresponding lever 17 or 52 will beraised, and the leg action can be changed in any position of the pedalat any point in time. In the case of applying a simultaneous and equalpressure to the two pedals the pedals will function as leg supports, andthe bicycle will move by inertia. When the pedals are provided with footclips, the pushing action of one pedal can be complemented with apulling action of the other pedal to increase the poser of the bicycledrive. The levers will move about a horizontal axis with a generalrolling angle of 90 degrees. The levers may telescope to attain a highertransmission ratio.

If each unit 5, 38 (FIG. 7) is made integral with the correspondingdriving member 68 and 69, and the elements are connected by bayonet lock70, the forces produced by the levers 17 and 52 will be combined, andtherefore operation of the apparatus will be hereinafter described witha force applied only to the lever 17. Movement of the lever 17 causesthe relative helical motion generated in the helical transmissionincluding members 68 and 69 to be resolved thanks to the use of rollingsplines into rotational motion of member 77 and translation motion ofmember 68 and unit 5. As the unit 5 engages with the driving member 2,its translational motion is converted into rotation of the drivenmember 1. Rigid axial connection of members 68 and 69 ensures a helicalmotion of the driving member 36 and return travel of the lever 52. Inthe course of reverse movement of the lever 17 the motion will beconverted thanks to the transmission of forces from member 68 to member69 and unit 38.

To ensure reversal and braking after stopping the driven member 1 (FIG.8), the apparatus is provided with a multi- position switch. Themovement of lever 17 away from the operator causes the clearancesbetween the engaging surfaces of unit 87 and flange 89 of driven member2 to be distributed as follows: d>c, b<d, the unit 87 engaging with thedriving unit 2 on the locking surfaces. As a result, the driving member2 transmits rotation to the driven member 1. A reverse movement of thelever 17 causes engagement of the unit 87 with driving member 2 on theirsliding surfaces for the member 2 to execute idling movement. To reversethe rotation, the flexible plate 97 of the switch is moved to the otherend position, whereby the clearances are distributed as follows:

    a<b; d<c.

This will cause the opposite surfaces to engage with sliding and rollingfriction.

When plate 97 of the switch assumes the middle position and a<b, c<d,then with fixed lever 17 rotation of the driven member 1 to any sidewill be prevented because the unit 87 will engage with the drivingmember 2 on their locking surfaces.

The apparatus shown in FIG. 9 operates as follows. With the flexibleplate 109 in its middle position and relationship between clearances a>band c>d, the driving member 2 executes reciprocating helical motionrelative to the driven member 1, since the driven member 1 is connectedto the actuating mechanism and has a substantial moment of inertia. Adirect force applied to the driven member 1 will cause this member 1 torotate the driving member 2. The driving member 2 will engage with thedriven member 1 on rolling friction surfaces thereby failing to renderresistance to rotation. When the flexible plate 109 is brought by handle108 to one of its end positions, rod 105 of the switch will turn toresult in a relative displacement and locking of the flanges of the unit100 and disk 101 of the driving member 2. In this case the clearances a,b, c, d will be distributed so that the movement of the driving member 2to one direction causes engagement of the locking surfaces, and themovement thereof to the opposite direction will engage the slidingsurfaces, and therefore the motion will be converted to one side,whereas rotation to the other side will be prevented.

The use of two helical mechanisms I and II (FIG. 10) ensures continuousrotation to any side and prevents rotation to the opposite direction.The driven members 1 and 113 rotating in any direction can be braked byturning the switch to different end positions to ensure movement indifferent directions. In the middle position of the switch free rotationof the driven members 1 and 113 to any side is ensured.

With the provision of mechanisms 138, 139 (FIG. 11) for generating andvarying a torque transmitted to the unit 140 for applying an axial forcethe apparatus operates in the following manner. When pressure is exertedon the lever 146, forces are transmitted through the connecting rod 144,rod 143, and projection 148 to the unit 140 which acts on the flange 4of the driving member 2. At the same time, lever 138 of the mechanismproduces a torque directed to the side of rotation of the drivenmember 1. The threaded connection of screw 2 and driven nut 1 withintermediate rolling bodies functions as a spline joint to transmittorque to the driven member 1 and wheel 21.

When reversing the driving member 2, intermediate rolling bodies 7 acton this member for it to execute helical motion relative to the drivenmember 1 rotating in the same direction. The flanges of unit 140 anddriving member 2 fail to engage due to the presence of a clearance "m"therebetween. Having accelerated the inertia mechanism to definite rpm,it is possible to terminate the action, whereby the members 2, 1, andwheel 21 will rotate by inertia.

After the acceleration, when high torques are no longer needed, levers138 and 139 of the mechanisms for producing and varying torque arelocked by the stop member 142 relative to the rod 143, and rotation isproduced only by the lever 146. When the moment of resistance torotation becomes substantial, two levers 139 and 146 are operated.

In view of the afore described, the invention makes it possible tomaterialize the idea of an endless screw by virtue of a differencebetween the magnitudes of rolling and sliding frictions, low moment ofinertia of the driving member 2 (FIG. 1) compared to the loadingcapacity of the helical transmission, and capacity to transmit rotationenergy from one rotating helical member to the other and execute helicalmotion of one such member relative to the other under the action ofaxial forces. In turn, this affords the following advantages:

to enhance the efficiency of energy conversion to 80-95%;

to use the apparatus both for generating a motion and for braking;

to execute a joint action of reversal, braking after stopping of thedriven member, and free rotation in any direction;

to automatically obtain idling motion in response to the movement of thedriven member 1;

to vary the displacement of the driving member 2 within its travel pathat any time, in any position thereof, at any allowable speed;

at a preset direction of motion to prevent rotation to the oppositedirection;

to ensure a continuous torque of the driven member 1;

to arbitrarily change the amplitude, frequency, and position of thedriving member 9;

to execute a braking action through changing the direction of forcesacting on the driven member 9, 42;

to ensure separate operation and change relative engagement of thedriving member 9, 42, to provide their independent action on the drivingmembers 2, 36, to synchronize the operation of the driving members 9,42, and to combine the forces produced thereby;

to obtain one revolution of the driven member 1 at small lineardisplacements of the driving member; and

to exceed the speed of rotation of the driven member which the latterassumes as it is acted upon by the driving member.

INDUSTRIAL APPLICABILITY

The invention can be used with success in in many fields of mechanicalengineering. The invention may be employed with advantage as energyconverters in such muscle-operated vehicles as bicycles, wheelchairs,pedal-driven vehicles for children, training equipment, parkattractions, and the like. In power engineering the proposed inventionmay be used primarily for wave power conversion.

I claim:
 1. An apparatus for converting reciprocating motion intounidirectional rotation, comprising:a nonself-locking screw drivemechanism accomodated in said casing; a first driving member of saidnonself-locking screw drive mechanism; sliding and locking surfaces ofsaid first driving member, a flange of said first driving member, anexternal cylindrical surface provided with a first-sense thread; a firstplurality of rolling bodies of said nonself-locking screw drivemechanism; a first driven member of said nonself-locking screw drivemechanism, having an axis of rotation and being associated with saidfirst driving member through the rolling bodies of said first plurality,said first driving member being rotatable about said axis of rotation; afirst axial force generating mechanism adapted also for developing atorque intended for changing the angle of turn of said first drivenmember; a first axial force application unit of said nonself-lockingscrew drive mechanism, associated with said first axial force generatingmechanism; sliding and locking surfaces of said first axial forceapplication unit; end face of said first force application unit, facingtowards said flange of said first driving member; clearances betweensaid locking surfaces of said first driving member and said first axialforce application unit; said first driving member associated with saidfirst axial force application unit and capable of free axial motion,free rotation and locking, as well as of cooperating, through saidlocking and said sliding surfaces thereof, with said locking and saidsliding surfaces of said first axial force application unit; a firstaxial force changing mechanism of said nonself-locking screw drivemechanism, associated with said first axial force application unit, afirst lever of said first axial force changing mechanism; a first screwdrive of said first axial force generating mechanism, a first drivemember of said first screw drive arranged coaxially with said firstdriven member and rigidly coupled to said first axial force applicationunit and said axial force changing mechanism for interaction with saidfirst driving and said first driven member, a second plurality ofrolling bodies of said first screw drive, a first stationary fixeddriven member associated with said first drive member through therolling bodies of said second plurality, an interior space of the firstdrive member.
 2. An apparatus according to claim 1, comprising:a seconddriving member arranged coaxially with said first driving member andassociated with said first force application unit so as to interacttherewith; an external cylindrical surface of said second driving memberhaving a thread of a sense opposite to that of said thread of said firstdriving member; a third plurality of rolling bodies; a second drivenmember rigidly coupled to said first driven member and associated,through the rolling bodies of said third plurality, with said seconddriving member; a brake unit rigidly coupled to said drive member ofsaid screw drive and adapted to interact with said second driven member;a brake unit rigidly coupled to said drive member of said screw driveand adapted to interact with said second driven member.
 3. An apparatusaccording to claim 1, comprising:a third driven member; a fourthplurality of rolling bodies; a third driving member arranged coaxiallywith said first driving member and associated with said third drivenmember through the rolling bodies of said fourth plurality; sliding andlocking surfaces of said third driving member; a second axial forcegenerating mechanism capable also of developing a torque intended forchanging the angle of turn of said third driven member; a second screwdrive of said second axial force generating mechanism, a second drivemember of said second screw drive arranged coaxially with said firstdrive member; a fifth plurality of rolling bodies of said second screwdrive, a second stationary fixed drive member of said second screw driveassociated with said second drive member through the rolling bodies ofsaid fifth plurality; end surfaces of said first and second drivemembers, facing each other; an interior space of said second drivemember; a sixth plurality of rolling bodies interposed between said endsurfaces facing each other; a second axial force application unitassociated with said third driving member and second drive member;locking and sliding surfaces of said second axial force applicationunit; clearances between said locking surfaces of said third drivingmember and second axial force application unit; clearances between saidsliding surfaces of said third driving member and second axial forceapplication unit; a second axial force changing mechanism associatedwith said second axial force application unit; a second lever of saidsecond axial force changing mechanism; a first plurality of bearings; asecond plurality of bearings; said casing built up to two components; afirst component of said casing associated, through the bearings of saidfirst plurality, with said first driven member and said secondstationary fixed drive member; a second component of said casingassociated, through the bearings of said second plurality, with saidthird driven member and second stationary fixed drive member.
 4. Anapparatus according to claim 1, comprising:a first multiposition switchadapted for reversal and braking action after said first driven memberhas stopped, and arranged with a possibility of being moved and lockedwith respect to said first axial force application unit, whereby thereis attained braking of said first driven member when rotating in anysense, as well as free rotation of said first driven member in eithersense and prevention of its rotation in the opposite sense; lockingsurfaces on each side of said first axial force application unit andfirst driving member, said surfaces facing each other; clearancesbetween said locking surfaces; sliding surfaces on each side of saidfirst axial force application unit and first driving unit, said surfacesfacing each other; clearances between said sliding surfaces; with saidfirst multiposition switch in the position corresponding to brakingaction, a total amount of said clearances between said locking surfacesof said first axial force application unit and first driving member isless than a total amount of said clearances between said slidingsurfaces; the amount of said clearances between the locking surfaces oneach side of said axial force application unit and said driving unit isless than the amount of said clearances between the sliding surfaces. 5.An apparatus according to claim 1,wherein said locking surfaces of saidfirst driving member and first axial force application unit are made ofsteel, said sliding surfaces are established by rolling bodies, and saidend face of said first axial force application unit has projectionswhose pointed tips contact said flange of said first driving member. 6.An apparatus according to claim 1, comprisingfriction elements ofprogressive and emergency braking, which are situated on the oppositesides of said first axial force application unit, adjustable stopsadapted for preventing or ensuring cooperation between said first axialforce application unit and said first driven member through saidfriction elements of progressive and emergency braking.
 7. An apparatusaccording to claim 3, comprising:an elastic linkage intended forestablishing interaction of said first and second drive members; firstprojections provided on the surface of said interior space of saidsecond drive member; second projections provided on the surface of saidinterior space of said second drive member; a first spring of saidelastic linkage, said spring being accommodated in said interior spaceof said first drive member and resting against said first projections; asecond spring of elastic linkage, said spring being accommodated in saidinterior space of said second drive member and resting against saidsecond projections; an adjusting screw accommodated inside said firstand second springs; thrust bearings contacting said first and secondsprings; said first and second springs intended for pressing said firstand second drive members against each other through the rolling bodiesof said sixth plurality and with the aid of said adjusting screw andthrust bearings; a brake mechanism; an elastic element of said brakemechanism rigidly coupled with said first axial force application unitand capable of cooperating with the second axial force application unit;brake shoes of said elastic element, and brake shoes being adapted tointeract with said first driven member when said first and second leversare acted upon by unidirectionally applied forces.
 8. An apparatusaccording to claim 3, comprisingrigid elements situated in said interiorspaces of said first and second drive members; said first and seconddrive members interlinked through the rolling bodies of said sixthplurality and said rigid elements with a possibility of mutual rotationand simultaneous unidirectional motion, the motion of said drive membersin the opposite directions being precluded.
 9. An apparatus according toclaim 3,wherein said first axial force application unit is made integralwith said first drive member, said second axial force application unitis made integral with said second drive member, said first and secondaxial force application units are rigidly interlinked, and said firstand second drive members are associated, through rolling-contactsplines, with said respective first and second components of saidcasing, with which components are also associated said respective firstand second stationary fixed drive members with a possibility ofrotation; additionally, said first and second components of said casinghave annular spaces adapted to accommodate said first and third drivenmembers, and said first and third driving members.
 10. An apparatusaccording to claim 3, comprising:second and third multiposition switchescapable of reversing continuous rotation, free unidirectional rotationof said first and third driven members and prevention of their rotationin the opposite directions, free rotation of said second and thirdmultiposition switches with a possibility of being moved and locked withrespect to said respect first and second axial force application units;when each of said second and third multiposition switches assumes theposition corresponding to braking action, a total amount of saidclearances between said locking surfaces of said first axial forceapplication unit and first driving member, and of said second axialforce application unit and third driving member is larger than a totalamount of said clearances between said sliding surfaces of said axialforce application units and said driving members; the amount of saidclearances between the locking surfaces on each side of said axial forceapplication unit and said driving unit is larger than the amount of saidclearances between the sliding surfaces.
 11. An apparatus according toclaim 4,wherein said first multiposition switch comprises thrust racerings of bearings, rolling bodies accommodated in said thrust racerings, a sliding nut associated with said thrust race rings, said nutbeing located on the first drive member reciprocatingly lengthwise saidfirst drive member and having an operating handle adapted forinteracting of said locking and sliding surfaces of said first axialforce application unit and first driving member when reversing andbraking after said first driven member has come to a standstill.
 12. Anapparatus according to claim 5, comprisinga torque generating mechanism,said torque being transmitted to said first axial force application unitassociated with said mechanism, and a torque changing mechanism thatvaries the torque in compliance with changes in the axial force applied,both of said mechanisms being connected to each other.
 13. An apparatusaccording to claim 6,wherein said adjustable stops are made of anelastic material.
 14. An apparatus according to claim 10, comprisingafirst hollow rod of said second multiposition switch, said rod beingrigidly coupled to said first axial force application unit, a secondhollow rod of said third multiposition switch, said rod being rigidlycoupled to said second axial force application unit, a first operatinghandle provided with a retainer and associated with said first hollowrod for said rod to lock and reciprocate axially with respect to thefirst drive member, a second operating handle provided with a retainerand associated with said second hollow rod for said rod to lock andreciprocate axially with respect to the second drive member;radial-thrust race rings rigidly coupled to said first drive member, androlling bodies fitted in said radial-thrust race rings to establishconnection between said first driving member and first drive member;said radial-thrust race rings rigidly coupled to said second drivemember, and rolling bodies fitted in said radial-thrust race rings toestablish connected between said third driving member and second drivemember; each of said first axial force application unit and said secondaxial force application unit has an additional locking surface foracting on said first driving member and said third driving member,respectively, with an additional force.
 15. An apparatus according toclaim 12,wherein said torque generating mechanism comprises a lockingmechanism that establishes a rigid coupling between said torquegenerating mechanism and said first axial force changing mechanism. 16.An apparatus according to claim 12,wherein said first axial forcechanging mechanism and a torque changing mechanism are integrated into asingle mechanism which is in effect a telescopic lever associated withsaid first drive member rigidly coupled to said first axial forceapplication unit.